Embodiments of this disclosure generally relate to vent systems in aircraft, and more particularly, to a pressure regulating float valve for the control of fuel entering into a fuel surge tank from the wing fuel tank of a fuel system.
Aircraft with swept wings and integral wing fuel tanks may use float valves on their outboard tanks to prevent excess fuel transfer to the fuel surge tanks during rotation or other maneuvers. The float valve may have a float and seal plate inside the wing fuel tank. The float valve may have a see-saw type pivot design. The float valve may be opened to allow for pressure equalization between the wing fuel tank and the surge fuel tank.
During certain maneuvers on the ground and in flight, fuel movement within the fuel tanks may result in the float valves closing and preventing the wing tank from venting. If the pressure inside the tank increases significantly due to altitude changes or fuel transfer or inert gas injection while the float valve is closed, damage to the fuel tank structure may occur. Alternatively, the tank structure may be suitably sized to withstand such pressure increases. However, this may increase the weight of the airplane and affect performance.
Therefore, it would be desirable to provide a vent system for an aircraft and methods thereof that overcome the above problems.